Good morning,
I’m looking to build a small desktop set for work using this enclosure:
Denovo Audio Knock-Down MDF 0.04 cu. ft. Micro Bookshelf Speaker Cabinet Pair
It will be driven off of a small class D amp.
My main question is whether there’s something that can be used full range with a passive radiator such as this:
Peerless by Tymphany 830878 3-1/2" Passive Radiator
The reason I’m asking is because all of the builds I’ve seen for this box with a PR have a tweeter. I’m not completely opposed to using sealed it’s just that I would prefer to have more bass if possible.
I know this is all a lot to ask for (no sub, tiny box, one driver, literally any audible bass at low volumes) but my expectations aren’t that high and the competition is a JBL Bluetooth tube speaker which sounds quite bad but was free.
Thanks for any suggestions
Mike
I’m looking to build a small desktop set for work using this enclosure:
Denovo Audio Knock-Down MDF 0.04 cu. ft. Micro Bookshelf Speaker Cabinet Pair
It will be driven off of a small class D amp.
My main question is whether there’s something that can be used full range with a passive radiator such as this:
Peerless by Tymphany 830878 3-1/2" Passive Radiator
The reason I’m asking is because all of the builds I’ve seen for this box with a PR have a tweeter. I’m not completely opposed to using sealed it’s just that I would prefer to have more bass if possible.
I know this is all a lot to ask for (no sub, tiny box, one driver, literally any audible bass at low volumes) but my expectations aren’t that high and the competition is a JBL Bluetooth tube speaker which sounds quite bad but was free.
Thanks for any suggestions
Mike
Don't expect real bass in such a small box, but quiet a few TB W3 models will go to arround 100Hz in such an enclosure with a PR or a port. But for real bass you need some volume.
I do have a pair of W3-881.
The only 3” driver i havw played with that fits such a small box is the Scan 10F (really a midrange) that is popular. 0.8 litres + vent.
Here one that was 3D printed:
https://frugal-phile.com/boxlib/nScan-Ken-0v9-220515.pdf
Note. A PR is just an expensive vent for boxes that are small with big vents.
dave
The only 3” driver i havw played with that fits such a small box is the Scan 10F (really a midrange) that is popular. 0.8 litres + vent.
Here one that was 3D printed:
https://frugal-phile.com/boxlib/nScan-Ken-0v9-220515.pdf
Note. A PR is just an expensive vent for boxes that are small with big vents.
dave
I'm getting 35Hz with a box this size, but only at desktop SPLs.
Sealed & (lots of) EQ is how I did it, but adding a PR would improve the main driver's mechanical power handling.
Chris
I might just go with a 1" port and use winISD to estimate what length I need. At first I wanted a PR but maybe the port will be cleaner looking and less trouble to tune. The W3-1878 sounds nearly ideal for that box size I think.
Hmm, the listed PR's resonance is fixed at 29 Hz, so no little high Fs driver in 1 L will excite it, ergo effectively a sealed cab. 🙁
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So? The equivalent vent volume will be several times Vas, so find it hard to believe the driver can move it, especially since its Xmax can only handle 1 W vented 100 Hz tuning with a 3/4" dia. x 2" long pipe vent, so at 7+ x more Xmax required to get to 29 Hz..........
I did a SB65WBAC25-4 as vented and also a PR in 1.3 litres and would also work in 1 litre giving output to below 70Hz with Fb=85Hz. The PR was the SB12PAC-00 but removed 40% of the spider to raise the Fs and for the smaller box about 50% would need to be removed.
Not much power handling but works fine and loud enough with the computer via a Dragonfly on the desktop with a DTA-2 (about 8W).
Not much power handling but works fine and loud enough with the computer via a Dragonfly on the desktop with a DTA-2 (about 8W).
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Yeah, didn't see any way to mod it for a higher Fs, so would need to make one from a cheap driver with a roll surround, but a small vent and a high pass filter seems the easiest, cheapest.
Seriously? 3/4" pvc pipe - Google Search
Regardless, in retrospect I should have pointed out that @ ~38 m/s peak vent mach the vent will be outputting mostly just a 'choking' noise since it ideally needs to be < ~5% of 344 m/s = ~17.2 m/s, though some claim up to ~25 m/s is acceptable in a sub [yours isn't], ergo need to go bigger diameter = longer.
Cutting the speed ~ in half [simmed ~18 m/s] = 1.5" dia. pipe x 8.875"/~111 Hz tuning, so going lower = longer with 75 Hz Fs tuning = 18.875", which has a very rolled off response due to small cab, acoustically small vent area.
Regardless, in retrospect I should have pointed out that @ ~38 m/s peak vent mach the vent will be outputting mostly just a 'choking' noise since it ideally needs to be < ~5% of 344 m/s = ~17.2 m/s, though some claim up to ~25 m/s is acceptable in a sub [yours isn't], ergo need to go bigger diameter = longer.
Cutting the speed ~ in half [simmed ~18 m/s] = 1.5" dia. pipe x 8.875"/~111 Hz tuning, so going lower = longer with 75 Hz Fs tuning = 18.875", which has a very rolled off response due to small cab, acoustically small vent area.
I see, thanks, maybe I should re evaluate using a modified passive radiator then. I just didn’t want to use straight pipe because I want it to look nice lol…